Biomimetic Calcification Guided Protein-Based Multifunctional Bio-Separators Realizing Dendrites Free and High-Performance Lithium-Sulfur Batteries

Abstract

Lithium-sulfur batteries (LSB) are considered promising energy storage systems owing to their high theoretical energy density and abundant sulfur resources. However, issues such as polysulfide shuttle, uneven lithium-ion transport, and lithium dendrite growth severely limit their practical deployment. Herein, a biomimetic calcification strategy was employed to fabricate a multifunctional separator by integrating ZIF-8 nanocrystals with β-sheet silk fibroin (β-SF) membranes. The β-SF served as a biological scaffold to direct the uniform deposition and growth of ZIF-8, yielding a composite separator with a high surface area and a porous architecture. Cryo-electron microscopy (Cryo-EM) confirmed that the highly ordered molecular alignment and abundant polar groups within the β-SF membrane effectively suppress lithium dendrite formation at the anode. Complementary theoretical calculations demonstrated that the bioinspired ZIF-8 component provides well-defined ion transport channels and strong adsorption sites, promoting uniform Li+ flux and enhancing lithium polysulfide (LiPSs) anchoring. This study highlights the advantages of multifunctionalization of biomimetic calcification coordinated composite separators and provides new avenues and insights for exploring multifunctional LSB separators.

Keywords: Biomimetic calcification, lithium-sulfur batteries, Multifunctional separator, Secondary structure transition, Proteins